1. Field of the Invention
The present invention relates to a food intake regulator, which contains a fish or mammalian melanin-concentrating hormone (MCH) and related substances thereof as an active ingredient. The food intake regulator according to the invention is useful in treatment of a disease and improvement of the symptom of the disease that are due to overeating or that require feeding regulation. Therefore, the food intake regulator according to the invention can be widely applied to various foods and pharmaceuticals.
2. Description of the Related Art
About more than half of men and women in their 40s or higher are patients or potential patients of lifestyle-related diseases such as hypertension, diabetes mellitus, and hyperlipidemia. Since most of these diseases are due to obesity, it is desired that obesity be prevented or improved. The best approach to preventing obesity is considered to setting of a regular eating pattern, but it is often difficult to establish and maintain the pattern in the modern age as a time of plenty.
As a substance which regulates, especially suppresses food intake, mazindol as amphetamines is commercially available as a pharmaceutical. However, the use of mazindol is limited only to patients having severe obesity because of the direct effects of mazindol on the central nervous system and risks of habituation or addiction. Safer approaches for the food intake regulation have been required.
As a method of suppressing food intake, Japanese Patent Laid-Open No. 2000-515139 discloses one using precursors of serotonin, dopamine, norepinephrine and histamine; Japanese Patent Laid-Open No. 1997-20675 discloses one using a fruit body of pleurotus ostreatus; and Japanese Patent Laid-Open No. 2002-53474 discloses one using avocado.
It is known that various hormones involved in food intake are present in the brain. As food intake stimulators, there are melanin-concentrating hormone (MCH), neuropeptide Y, peptide YY, AgRP, ghrelin, and noradrenaline, while, as biologically active substances for food intake regulators, there are α-melanocyte-stimulating hormone (α-MSH), serotonin, cholecystokinin (CCK), and glucagon-like peptide-1 (GLP-1).
Melanin-concentrating hormone (MCH), which was first identified as a substance adaptively controlling pigment aggregation in the pituitary gland of salmon of fishes, was also found in the hypothalamus of the mammalian brain and attracts attention as a hormone involved in food intake. Significant body weight loss was found in MCH gene knockout mice with decreased food intake and increased metabolism (Shimada. M, et al., Nature, 396, 670-674, 1998). In addition, after MCH was injected intracerebroventricularly to rats, it was found to stimulate food intake (M. Rossi, et. al., Endocrinology, 138, 351-355, 1997).
Thus, an antagonist of the receptor for MCH as a food intake stimulator is expected to provide a food intake regulator. For this reason, many MCH receptor antagonists have been developed and expected to provide an anti-obesity agent, such as the food intake regulator i T-226296 (Takekawa, S., et. al., European Journal of Pharmacology, 438(3), 129-135, 2002).